<?php
/**
 * Zend Framework
 *
 * LICENSE
 *
 * This source file is subject to the new BSD license that is bundled
 * with this package in the file LICENSE.txt.
 * It is also available through the world-wide-web at this URL:
 * http://framework.zend.com/license/new-bsd
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@zend.com so we can send you a copy immediately.
 *
 * @category   Zend
 * @package    Zend_Pdf
 * @subpackage Fonts
 * @copyright  Copyright (c) 2005-2009 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 * @version    $Id: CidFont.php 18993 2009-11-15 17:09:16Z alexander $
 */

/** Internally used classes */
require_once 'Zend/Pdf/Element/Array.php';
require_once 'Zend/Pdf/Element/Dictionary.php';
require_once 'Zend/Pdf/Element/Name.php';
require_once 'Zend/Pdf/Element/Numeric.php';
require_once 'Zend/Pdf/Element/String.php';


/** Zend_Pdf_Resource_Font */
require_once 'Zend/Pdf/Resource/Font.php';

/**
 * Adobe PDF CIDFont font object implementation
 *
 * A CIDFont program contains glyph descriptions that are accessed using a CID as
 * the character selector. There are two types of CIDFont. A Type 0 CIDFont contains
 * glyph descriptions based on Adobe’s Type 1 font format, whereas those in a
 * Type 2 CIDFont are based on the TrueType font format.
 *
 * A CIDFont dictionary is a PDF object that contains information about a CIDFont program.
 * Although its Type value is Font, a CIDFont is not actually a font. It does not have an Encoding
 * entry, it cannot be listed in the Font subdictionary of a resource dictionary, and it cannot be
 * used as the operand of the Tf operator. It is used only as a descendant of a Type 0 font.
 * The CMap in the Type 0 font is what defines the encoding that maps character codes to CIDs
 * in the CIDFont.
 *
 * Font objects should be normally be obtained from the factory methods
 * {@link Zend_Pdf_Font::fontWithName} and {@link Zend_Pdf_Font::fontWithPath}.
 *
 * @package    Zend_Pdf
 * @subpackage Fonts
 * @copyright  Copyright (c) 2005-2009 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 */
abstract class Zend_Pdf_Resource_Font_CidFont extends Zend_Pdf_Resource_Font
{
	/**
	 * Object representing the font's cmap (character to glyph map).
	 * @var Zend_Pdf_Cmap
	 */
	protected $_cmap = null;

	/**
	 * Array containing the widths of each character that have entries in used character map.
	 *
	 * @var array
	 */
	protected $_charWidths = null;

	/**
	 * Width for characters missed in the font
	 *
	 * @var integer
	 */
	protected $_missingCharWidth = 0;


	/**
	 * Object constructor
	 *
	 * @param Zend_Pdf_FileParser_Font_OpenType $fontParser Font parser object
	 *   containing OpenType file.
	 * @param integer $embeddingOptions Options for font embedding.
	 * @throws Zend_Pdf_Exception
	 */
	public function __construct(Zend_Pdf_FileParser_Font_OpenType $fontParser)
	{
		parent::__construct();

		$fontParser->parse();


		/* Object properties */

		$this->_fontNames = $fontParser->names;

		$this->_isBold       = $fontParser->isBold;
		$this->_isItalic     = $fontParser->isItalic;
		$this->_isMonospaced = $fontParser->isMonospaced;

		$this->_underlinePosition  = $fontParser->underlinePosition;
		$this->_underlineThickness = $fontParser->underlineThickness;
		$this->_strikePosition     = $fontParser->strikePosition;
		$this->_strikeThickness    = $fontParser->strikeThickness;

		$this->_unitsPerEm = $fontParser->unitsPerEm;

		$this->_ascent  = $fontParser->ascent;
		$this->_descent = $fontParser->descent;
		$this->_lineGap = $fontParser->lineGap;


		$this->_cmap = $fontParser->cmap;


		/* Resource dictionary */

		$baseFont = $this->getFontName(Zend_Pdf_Font::NAME_POSTSCRIPT, 'en', 'UTF-8');
		$this->_resource->BaseFont = new Zend_Pdf_Element_Name($baseFont);


		/**
		 * Prepare widths array.
		 */
		/* Constract characters widths array using font CMap and glyphs widths array */
		$glyphWidths = $fontParser->glyphWidths;
		$charGlyphs  = $this->_cmap->getCoveredCharactersGlyphs();
		$charWidths  = array();
		foreach ($charGlyphs as $charCode => $glyph) {
			$charWidths[$charCode] = $glyphWidths[$glyph];
		}
		$this->_charWidths       = $charWidths;
		$this->_missingCharWidth = $glyphWidths[0];

		/* Width array optimization. Step1: extract default value */
		$widthFrequencies = array_count_values($charWidths);
		$defaultWidth          = null;
		$defaultWidthFrequency = -1;
		foreach ($widthFrequencies as $width => $frequency) {
			if ($frequency > $defaultWidthFrequency) {
				$defaultWidth          = $width;
				$defaultWidthFrequency = $frequency;
			}
		}

		// Store default value in the font dictionary
		$this->_resource->DW = new Zend_Pdf_Element_Numeric($this->toEmSpace($defaultWidth));

		// Remove characters which corresponds to default width from the widths array
		$defWidthChars = array_keys($charWidths, $defaultWidth);
		foreach ($defWidthChars as $charCode) {
			unset($charWidths[$charCode]);
		}

		// Order cheracter widths aray by character codes
		ksort($charWidths, SORT_NUMERIC);

		/* Width array optimization. Step2: Compact character codes sequences */
		$lastCharCode = -1;
		$widthsSequences = array();
		foreach ($charWidths as $charCode => $width) {
			if ($lastCharCode == -1) {
				$charCodesSequense = array();
				$sequenceStartCode = $charCode;
			} else if ($charCode != $lastCharCode + 1) {
				// New chracters sequence detected
				$widthsSequences[$sequenceStartCode] = $charCodesSequense;
				$charCodesSequense = array();
				$sequenceStartCode = $charCode;
			}
			$charCodesSequense[] = $width;
			$lastCharCode = $charCode;
		}
		// Save last sequence, if widths array is not empty (it may happens for monospaced fonts)
		if (count($charWidths) != 0) {
			$widthsSequences[$sequenceStartCode] = $charCodesSequense;
		}

		$pdfCharsWidths = array();
		foreach ($widthsSequences as $startCode => $widthsSequence) {
			/* Width array optimization. Step3: Compact widths sequences */
			$pdfWidths        = array();
			$lastWidth        = -1;
			$widthsInSequence = 0;
			foreach ($widthsSequence as $width) {
				if ($lastWidth != $width) {
					// New width is detected
					if ($widthsInSequence != 0) {
						// Previous width value was a part of the widths sequence. Save it as 'c_1st c_last w'.
						$pdfCharsWidths[] = new Zend_Pdf_Element_Numeric($startCode);                         // First character code
						$pdfCharsWidths[] = new Zend_Pdf_Element_Numeric($startCode + $widthsInSequence - 1); // Last character code
						$pdfCharsWidths[] = new Zend_Pdf_Element_Numeric($this->toEmSpace($lastWidth));       // Width

						// Reset widths sequence
						$startCode = $startCode + $widthsInSequence;
						$widthsInSequence = 0;
					}

					// Collect new width
					$pdfWidths[] = new Zend_Pdf_Element_Numeric($this->toEmSpace($width));

					$lastWidth = $width;
				} else {
					// Width is equal to previous
					if (count($pdfWidths) != 0) {
						// We already have some widths collected
						// So, we've just detected new widths sequence

						// Remove last element from widths list, since it's a part of widths sequence
						array_pop($pdfWidths);

						// and write the rest if it's not empty
						if (count($pdfWidths) != 0) {
							// Save it as 'c_1st [w1 w2 ... wn]'.
							$pdfCharsWidths[] = new Zend_Pdf_Element_Numeric($startCode); // First character code
							$pdfCharsWidths[] = new Zend_Pdf_Element_Array($pdfWidths);   // Widths array

							// Reset widths collection
							$startCode += count($pdfWidths);
							$pdfWidths = array();
						}

						$widthsInSequence = 2;
					} else {
						// Continue widths sequence
						$widthsInSequence++;
					}
				}
			}

			// Check if we have widths collection or widths sequence to wite it down
			if (count($pdfWidths) != 0) {
				// We have some widths collected
				// Save it as 'c_1st [w1 w2 ... wn]'.
				$pdfCharsWidths[] = new Zend_Pdf_Element_Numeric($startCode); // First character code
				$pdfCharsWidths[] = new Zend_Pdf_Element_Array($pdfWidths);   // Widths array
			} else if ($widthsInSequence != 0){
				// We have widths sequence
				// Save it as 'c_1st c_last w'.
				$pdfCharsWidths[] = new Zend_Pdf_Element_Numeric($startCode);                         // First character code
				$pdfCharsWidths[] = new Zend_Pdf_Element_Numeric($startCode + $widthsInSequence - 1); // Last character code
				$pdfCharsWidths[] = new Zend_Pdf_Element_Numeric($this->toEmSpace($lastWidth));       // Width
			}
		}

		/* Create the Zend_Pdf_Element_Array object and add it to the font's
		 * object factory and resource dictionary.
		 */
		$widthsArrayElement = new Zend_Pdf_Element_Array($pdfCharsWidths);
		$widthsObject = $this->_objectFactory->newObject($widthsArrayElement);
		$this->_resource->W = $widthsObject;


		/* CIDSystemInfo dictionary */
		$cidSystemInfo = new Zend_Pdf_Element_Dictionary();
		$cidSystemInfo->Registry   = new Zend_Pdf_Element_String('Adobe');
		$cidSystemInfo->Ordering   = new Zend_Pdf_Element_String('UCS');
		$cidSystemInfo->Supplement = new Zend_Pdf_Element_Numeric(0);
		$cidSystemInfoObject            = $this->_objectFactory->newObject($cidSystemInfo);
		$this->_resource->CIDSystemInfo = $cidSystemInfoObject;
	}



	/**
	 * Returns an array of glyph numbers corresponding to the Unicode characters.
	 *
	 * If a particular character doesn't exist in this font, the special 'missing
	 * character glyph' will be substituted.
	 *
	 * See also {@link glyphNumberForCharacter()}.
	 *
	 * @param array $characterCodes Array of Unicode character codes (code points).
	 * @return array Array of glyph numbers.
	 */
	public function glyphNumbersForCharacters($characterCodes)
	{
		/**
		 * CIDFont object is not actually a font. It does not have an Encoding entry,
		 * it cannot be listed in the Font subdictionary of a resource dictionary, and
		 * it cannot be used as the operand of the Tf operator.
		 *
		 * Throw an exception.
		 */
		require_once 'Zend/Pdf/Exception.php';
		throw new Zend_Pdf_Exception('CIDFont PDF objects could not be used as the operand of the text drawing operators');
	}

	/**
	 * Returns the glyph number corresponding to the Unicode character.
	 *
	 * If a particular character doesn't exist in this font, the special 'missing
	 * character glyph' will be substituted.
	 *
	 * See also {@link glyphNumbersForCharacters()} which is optimized for bulk
	 * operations.
	 *
	 * @param integer $characterCode Unicode character code (code point).
	 * @return integer Glyph number.
	 */
	public function glyphNumberForCharacter($characterCode)
	{
		/**
		 * CIDFont object is not actually a font. It does not have an Encoding entry,
		 * it cannot be listed in the Font subdictionary of a resource dictionary, and
		 * it cannot be used as the operand of the Tf operator.
		 *
		 * Throw an exception.
		 */
		require_once 'Zend/Pdf/Exception.php';
		throw new Zend_Pdf_Exception('CIDFont PDF objects could not be used as the operand of the text drawing operators');
	}


	/**
	 * Returns a number between 0 and 1 inclusive that indicates the percentage
	 * of characters in the string which are covered by glyphs in this font.
	 *
	 * Since no one font will contain glyphs for the entire Unicode character
	 * range, this method can be used to help locate a suitable font when the
	 * actual contents of the string are not known.
	 *
	 * Note that some fonts lie about the characters they support. Additionally,
	 * fonts don't usually contain glyphs for control characters such as tabs
	 * and line breaks, so it is rare that you will get back a full 1.0 score.
	 * The resulting value should be considered informational only.
	 *
	 * @param string $string
	 * @param string $charEncoding (optional) Character encoding of source text.
	 *   If omitted, uses 'current locale'.
	 * @return float
	 */
	public function getCoveredPercentage($string, $charEncoding = '')
	{
		/* Convert the string to UTF-16BE encoding so we can match the string's
		 * character codes to those found in the cmap.
		 */
		if ($charEncoding != 'UTF-16BE') {
			$string = iconv($charEncoding, 'UTF-16BE', $string);
		}

		$charCount = iconv_strlen($string, 'UTF-16BE');
		if ($charCount == 0) {
			return 0;
		}

		/* Calculate the score by doing a lookup for each character.
		 */
		$score = 0;
		$maxIndex = strlen($string);
		for ($i = 0; $i < $maxIndex; $i++) {
			/**
			 * @todo Properly handle characters encoded as surrogate pairs.
			 */
			$charCode = (ord($string[$i]) << 8) | ord($string[++$i]);
			/* This could probably be optimized a bit with a binary search...
			 */
			if (isset($this->_charWidths[$charCode])) {
				$score++;
			}
		}
		return $score / $charCount;
	}

	/**
	 * Returns the widths of the Chars.
	 *
	 * The widths are expressed in the font's glyph space. You are responsible
	 * for converting to user space as necessary. See {@link unitsPerEm()}.
	 *
	 * See also {@link widthForChar()}.
	 *
	 * @param array &$glyphNumbers Array of glyph numbers.
	 * @return array Array of glyph widths (integers).
	 */
	public function widthsForChars($charCodes)
	{
		$widths = array();
		foreach ($charCodes as $key => $charCode) {
			if (!isset($this->_charWidths[$charCode])) {
				$widths[$key] = $this->_missingCharWidth;
			} else {
				$widths[$key] = $this->_charWidths[$charCode];
			}
		}
		return $widths;
	}

	/**
	 * Returns the width of the character.
	 *
	 * Like {@link widthsForChars()} but used for one char at a time.
	 *
	 * @param integer $charCode
	 * @return integer
	 */
	public function widthForChar($charCode)
	{
		if (!isset($this->_charWidths[$charCode])) {
			return $this->_missingCharWidth;
		}
		return $this->_charWidths[$charCode];
	}

	/**
	 * Returns the widths of the glyphs.
	 *
	 * @param array &$glyphNumbers Array of glyph numbers.
	 * @return array Array of glyph widths (integers).
	 * @throws Zend_Pdf_Exception
	 */
	public function widthsForGlyphs($glyphNumbers)
	{
		/**
		 * CIDFont object is not actually a font. It does not have an Encoding entry,
		 * it cannot be listed in the Font subdictionary of a resource dictionary, and
		 * it cannot be used as the operand of the Tf operator.
		 *
		 * Throw an exception.
		 */
		require_once 'Zend/Pdf/Exception.php';
		throw new Zend_Pdf_Exception('CIDFont PDF objects could not be used as the operand of the text drawing operators');
	}

	/**
	 * Returns the width of the glyph.
	 *
	 * Like {@link widthsForGlyphs()} but used for one glyph at a time.
	 *
	 * @param integer $glyphNumber
	 * @return integer
	 * @throws Zend_Pdf_Exception
	 */
	public function widthForGlyph($glyphNumber)
	{
		/**
		 * CIDFont object is not actually a font. It does not have an Encoding entry,
		 * it cannot be listed in the Font subdictionary of a resource dictionary, and
		 * it cannot be used as the operand of the Tf operator.
		 *
		 * Throw an exception.
		 */
		require_once 'Zend/Pdf/Exception.php';
		throw new Zend_Pdf_Exception('CIDFont PDF objects could not be used as the operand of the text drawing operators');
	}

	/**
	 * Convert string to the font encoding.
	 *
	 * @param string $string
	 * @param string $charEncoding Character encoding of source text.
	 * @return string
	 * @throws Zend_Pdf_Exception
	 *      */
	public function encodeString($string, $charEncoding)
	{
		/**
		 * CIDFont object is not actually a font. It does not have an Encoding entry,
		 * it cannot be listed in the Font subdictionary of a resource dictionary, and
		 * it cannot be used as the operand of the Tf operator.
		 *
		 * Throw an exception.
		 */
		require_once 'Zend/Pdf/Exception.php';
		throw new Zend_Pdf_Exception('CIDFont PDF objects could not be used as the operand of the text drawing operators');
	}

	/**
	 * Convert string from the font encoding.
	 *
	 * @param string $string
	 * @param string $charEncoding Character encoding of resulting text.
	 * @return string
	 * @throws Zend_Pdf_Exception
	 */
	public function decodeString($string, $charEncoding)
	{
		/**
		 * CIDFont object is not actually a font. It does not have an Encoding entry,
		 * it cannot be listed in the Font subdictionary of a resource dictionary, and
		 * it cannot be used as the operand of the Tf operator.
		 *
		 * Throw an exception.
		 */
		require_once 'Zend/Pdf/Exception.php';
		throw new Zend_Pdf_Exception('CIDFont PDF objects could not be used as the operand of the text drawing operators');
	}
}
